This invention relates to decorative aluminum alloy products and a process for the manufacture of same. These products have a miracle and attractive surface and sectional appearance similar in its substance to a wooden or marble board. In addition, these products have an anticorrosive and wear-resistant surface.
It is broadly known to produce an anticorrosive and wear-resistant surface by anodizing or anodically oxidizing treatment of aluminum alloys.
This oxide surface layer can be colored variously by use of dyestuffs. Color shades of bronze tone can be also electrolytically produced on such oxide surface layer by suitably selecting the composition of the aluminum alloy and the electrolyte. These colored aluminum or aluminum alloy materials and products have various usage fields such as from decorative building materials to miracle personal accessories.
Various processes are known to provide a design pattern effect on these colored aluminum materials and products.
A simplest method adopted for this purpose is to apply partially the pigment color printing. A further method resides in a partial etching of a clad board consisting of two or more different aluminum alloy sheet elements for the formation of irregular recesses of different depths, thereby producing difference in color depending upon the alloy composition of the exposed layer. In this respect, reference may be had to U.S. Patent Application Ser. No. 314,319 (1963).
It is further known to produce a crystal grain pattern through the way of etching, as disclosed in the specifications of U.S. Pat. No. 2,941,930 and U.S. patent application Ser. No. 154,475 (1971).
A common feature to these several known processes resides in the preparation of plane decorative sheets or boards and thus, they can not be applied to three-dimensional products. In addition, the thus obtained design pattern is rather monotonous. It is therefore inhibitingly difficult to provide a highly miracle and attractive complexed light-and-dark design pattern in resemblance to natural wood grain or marble-like appearance onto the surface of a three-dimensional product by reliance to these known process. It is further impracticable to provide a mirror finish to such decorative surface by virtue of the disappearance of the surface design pattern during the finishing operation.